A gesture lock is a common user encryption and decryption mode on a touch-screen electronic device. Normally, an interface presented by a gesture-locking touch screen to a user is a graphic receiving interface similar to a nine-square grid, and the graphic receiving interface may consist of several points. To use encrypted information on the electronic device or open the touch screen of the electronic device, first, the user connects points that the user sets in advance on the graphic receiving interface of the gesture-locking touch screen to form a touch graphic; the electronic device verifies the touch graphic and then provides information to the user or opens the touch screen of the electronic device. The touch graphic refers to a graphic created by the user by sliding a finger or a stylus pen on the graphic receiving interface to connect multiple points.
Applications of gesture-locking touch screens replace an earlier encryption and decryption mode of manually inputting a character password, which brings the simple and easy-to-use features of the touch-screen electronic device into full play. For example, as shown in FIG. 9, when the user puts a gesture lock on encrypted information or on the touch screen, the user connects several points on the graphic receiving interface similar to a nine-square grid to form a touch graphic of a capital “Z.” Circles in FIG. 9 indicate the points, and arrows indicate sliding directions and sliding traces made by a finger or a stylus pen on the touch screen, where the sliding traces connect several points and form the touch graphic of a capital “Z.” When the user needs to unlock the encrypted information or the touch screen later, similarly, the user needs to connect several corresponding points to form the shape “Z” on the graphic receiving interface on the touch screen, thereby opening the encrypted information or the touch screen.
At present, gesture locks on electronic devices have been widely applied; however, when the user performs locking or unlocking on the touch screen, inevitably, sweat and grease on a finger may leave a clear track on the touch screen. Another user paying little attention may easily unlock the gesture lock according to the track on the touch screen, which threatens security of personal information of the user, and therefore decreases security of locking or unlocking with a touch graphic.